Persistent trans-synaptic stimulation or injection of a high dose of carbohydrate active steroids elicit a long-term increase of tyrosine hydroxylase (TH) activity in superior cervical ganglia (SCG). The induction of TH does not depend on an intact retrograde transport system of trophic substances and is not mediated by a second messenger response. Trans-synaptic stimulation elicits an increase in alpha-amanitin sensitive RNA-synthesis, whereas dexamethasone failed to do so. BIBLIOGRAPHIC REFERENCES: Hanbauer, I.: Induction of tyrosine-3-monooxygenase in superior cervical ganglia after axotomy of postganglionic nerves. Neuropharmacology 15: 509-510, 1976. Hanbauer, I.: Hormonal regulation of tyrosine hydroxylase. Symposium on Biochemical and Function of Monoamine Enzymes (Steamboat Springs) Usdin, Earl and Weiner, Norman (Eds.) Marcel Dekker, Inc., In press (1977).